Method and apparatus for combatting aircraft fires

ABSTRACT

A method of combatting aircraft fires consisting of hovering an emergency aircraft, usually a helicopter, above an aircraft which has crash-landed or is in distress and is about to crashland, said helicopter thereby being positioned immediately above the aircraft either during or immediately after the crash landing, and being specially equipped to emit clouds of flame-smothering vapors to envelop the aircraft in trouble, whereby either to prevent fires or to immediately extinguish fires which may start, thereby to save large numbers of lives and incalculable amounts of property damage, and the apparatus for performing said method.

169-45. OR 3,580,339 5R if M Q? i [72] Inventor David Nance 2,665,7681/1954 Talbot 169/36 R0. Box 16291, Phoenix, Ariz. 85011 2,779,4211/1957 Rust 169/1 [21] App]. No. 795,171 3,220,482 11/1965 Eveleth244/136X [22] Filed Jan. 30, 1969 3,442,334 5/1969 Gousetis 169/2 [45]Patented May 1971 Primary ExaminerLloyd L. King 54 METHOD AND APPARATUSFOR COMBATTING AIRCRAFT FIRES 5 Claims 2 Drawmg Flgs' ABSTRACT: A methodof combatting aircraft fires consisting [52] US. Cl 169/2, f h v rin anemergency aircraft, usually a helicopter, above 169/31, 69/36, 244/136an aircraft which has crash-landed or is in distress and is about [5 1]Int. Cl A62c 3/06 to crashland, Said helicopter thereby being positioned[50] Field ofSearch 169/l,2,

mediately above the aircraft either during or immediately 23, 30, 36;244/136 after the crash landing, and being specially equipped to emitclouds of flame-smothering vapors to envelop the aircraft in [56]References cued trouble, whereby either to prevent fires or toimmediately UNITED STATES PATENTS extinguish fires which may start,thereby to save large num- 2,003,300 6/1935 Meigs 169/36 bers of livesand incalculable amounts of property damage, 2,583,883 1/1952 Ripper244/136 and the apparatus for performing said method.

P TEB "M25 197i i 3,580,339

sum 1 OF 2 QUE] INVEN'I'OR. flaw/d Nance Attorney.

tragic multiplication of these loss figures is readily apparent.

The part played by fire in these losses is tremendous. A largepercentage of crashes and crash landings are not of the type which causeinstant death to all persons aboard, but are in fact crash landings ofvarying degrees of severity which many persons survive, though perhapsunconscious, injured or otherwise trapped in the aircraft. However, manyof these immediate survivors are subsequently killed by burning of thecrashed aircraft. Most, perhaps 90 percent of the aircraft which crashdo burn, the fires starting either at the instant of the crash, orwithin seconds thereafter. Most, again perhaps 90 percent, of aircraftcrashes occur either during landing at or takeoff from an airport, orwithin a radius of a very few miles from an airport. Nevertheless, anddespite the fact that at least the crew of a plane knows that a crashlanding is imminent some time before it occurs, and can notify groundcrews of this fact by radio, the crash landings often occur in areaswhich while close to an airport are difficult for fire trucks and otheremergency ground vehicles to reach in time to prevent or combat anyresultant fire effectively. In fact, even if a crash landing occursdirectly on an airfield, the resulting fire is often out of controlbefore crash trucks can reach the scene. i

Accordingly, the principal object of the present invention is theprovision of both an apparatus and method for more effectivelypreventing or fighting aircraft fires of the type described. Generally,the apparatus consistsof a helicopter, specially equipped to emitvoluminous clouds of flamesmothering vapor, mist, foam or the likedownwardly therefrom. In the method, said helicopter, at least one ofwhich could be based in a condition of continuous readiness at everyairport, responds to the radio call of an aircraft in distress whichknows it must crashland, taking to the air and positioning itself abovethe craft in distress and following it to its crash landing whileemitting its flame-smothering clouds. Thus the distressed aircraft landsin enveloping clouds of flamesmothering vapor or the like, and thechances that the crashed aircraft will burn are greatly reduced. If thefire does occur, the helicopter can reach the scene to fight the firemuch faster than any fire truck to better fight said fire.

If the helicopter arrives after a fire breaks out, or a fire shouldbreak out when the helicopter is hovering'above a crashed plane, theintense rising heat may of course make it impossible for the helicopterto remain in position above the crash. Accordingly, a further object isthe provision of means whereby the flame-smothering chemical of thehelicopter may be directed horizontally in any direction, so that thehelicopter may hover at the windward side of the crash and still fightthe flames effectively.

A still further object is the provision of means on the helicopter fordropping fire-fighting bombs." Such a bomb comprises a ball of rubber orthe like containing a pressurized chemical. The dropped bomb explodes oncontact with the ground and its contents are converted almost instantlyinto dense clouds of flame-smothering vapor. This permits a generallydenser concentration of the vapor around the crash than is possible fromthe more distantly positioned helicopter, and hence is generally moreeffective in fighting actual fires.

With these objects in view as well as other objects which will appear inthe course of the specification, reference will be had to theaccompanying drawing, wherein:

FIG. 1 is a diagram illustrating a method of combatting aircraft firesembodying the present invention, and including a helicopter constitutinga fire-fighting apparatus embodying the present invention, and

FIG. 2 is an inverted plan view of the helicopter tank, including aschematic diagram of the control system.

Like reference numerals apply to similar parts in both views of thedrawing, and the numeral 2 applies to an aircraft in distress, about tomake a crash landing on the ground 4. Let it be assumed that its pilothas radioed to a nearby airport that the crash landing is imminent. Aspecially equipped helicopter 6 is then dispatched to assume a positionas shown, over aircraft 2, and maintains this position as the aircraftmakes its crash landing. Before, during and after the crash landing, thehelicopter sometimes does not break out for some time after a crash, or

to fight and extinguish any fire which does occur.

Helicopter 6 is supported and propelled by the usual overhead blades 10,rotating on a vertical axis. These blades create a strong downdraft ofair around the helicopter and this downdraft has at least two valuablefunctions in the firefighting operation just described. First, it tendsto blow vapor clouds 8 downwardly to envelop aircraft 2 more rapidlythan it would otherwise occur, since the vapor, while heavier than airand capable of settling downwardly by gravity, would otherwisedo so moreslowly. Secondly, the downdraft creates a draft of large amounts ofcooler air from above downwardly over the helicopter itself. This tendsto protect the helicopter from the heat of a crashed plane which hasburst into flame, and thereby permits said helicopter to approach thecrash more closely than would otherwise be possible.

Attached to the bottom of the fuselage 12' of the helicopter, or builtinto the lower portion of said fuselage, is a large tank 14 adapted tocontain a liquid chemical which, when ejected from said tank underpressure into the atmosphere through suitable nozzles, is immediatelyconverted into clouds of vapor 'or the like from which air is largelyexcluded, whereby to prevent burning of any object enveloped therein,and to smother flames if the object is already burning. Such chemicalsare already commercially available. Said tank is equipped with aplurality of nozzles 16 adapted when open to direct chemical from saidtank downwardly, nozzles 18 adapted to direct said chemical forwardly,nozzles 20 adapted to direct said chemical horizontally to the right,and nozzles 24 adapted to direct said chemical horizontally to the left.The number of nozzles directed in each direction will of course bedetennined by the capacity of each nozzle and the delivery rate of thechemical which may be desired. The helicopter must of course be providedwith landing gear 26 extending far enough below fuselage 12 to protecttank 14 and the nozzles from damage when the helicopter lands.

Tank 14 is pressurized, whereby to eject the chemical firefightingliquid through any of the nozzles which are open, by air deliveredthereto through a conduit 26 from an air pump 28 driven by an electricmotor 30. Said motor is connected by wire 32 through a manually operableswitch 34 to the hot lead wire 36 of a battery 38 or other source ofelectric power. The opposite terminal of said battery is grounded at 40,and the opposite terminal of motor 30 is grounded at 42. Thus the motoris energized, and tank T4 is pressurized, whenever switch 34 is closed.

It will be understood that each of nozzles 16, 18, 20, 22 and 24includes electrically actuated control means operable to open saidnozzle whenever electric current is furnished thereto. Said controlmeans of all of nozzles 16 are connected by wires 44 through a singlemanually operable switch 46 to battery lead wire 36, the oppositeterminal of each control means being grounded at 48, whereby nozzles 16are opened whenever switch 46 is closed. Similarly, all of nozzles 18are connected by wire 50 to lead wire 36 through switch 52 and groundedat 54, all of nozzles 20 are connected by wire 56 to lead wire 36through switch 58 and grounded at 60, all of nozzles 22 are connected bywire 62 to lead wire 36 through I switch 64 and grounded at 66, and allof nozzles 24 are connected by wire 68 to lead wire 36 through switch 70and grounded at 72.-

Normally, if the helicopter can position itself directly above aircraft2, either before or after a crash landing, as is most desirable, onlynozzles 16 will be opened, by closure of switch 46. However, if thecrash landing has occurred and fire has broken out, the intense heat mayrender it impossible for the helicopter to maintain a position directlyabove aircraft 2. In these conditions, the helicopter may hover to oneside of the wreck, preferably the windward side, and open theappropriate nozzles 18, 20, 22 or 24, by closure of the correspondingswitches 52, 58, 64 or 70, to direct the fire-fighting chemicalhorizontally toward the wreck.

Also, the helicopter may carry a plurality of fire-fighting bombs" 74,each bomb consisting of a hollow ball formed of rubber of the like andcontaining a pressurized chemical firefighting material, so that whenthe bomb is dropped and strikes either the 'aircraft 2 or the groundnearly, it bursts and emits dense clouds of vapor or the like whichexclude air both to prevent and to smother fires. Each bomb is carriedin a bomb rack" 76 mounted on the helicopter, and which may constitute avertical tube open at its lower end. Each bomb is carried in one of saidracks, and is releasably retained therein by an electrically operablerelease mechanism 78 operable to release the associated bomb wheneverelectric current is supplied thereto. One terminal of each mechanism 78is connected by a wire 80 to battery lead wire 36 through a manuallyoperable switch 82, and the opposite terminal of each release mechanismis grounded at 84. Thus, each bomb 74 may be dropped whenever desired byclosing the associated switch 82. The bombs are generally capable ofSupplying a denser, thicker concentration of flame-smothering vapordirectly at and around a crashed aircraft than can be supplied by thenozzles, and hence are valuable tools for preventing or extinguishingfire in an aircraft which has already crashed, but they are of courseineffective to provide clouds of flame-smothering vapor to envelop theaircraft in trouble during its actual landing. Nozzles 18, 20, 22 and 24are preferably of a type capable of ejecting the liquid chemical inthinner, more streamlined jets than nozzles 16, which may be of a spraytype, whereby said jets travel farther from the nozzles, preferablyoutside of the strong downdraft of bladeslO, before bursting into cloudsof vapor. Thus the helicopter can hover at a substantial distance to theside of a wrecked plane and still fight the fire effectively, withoutthe flame fighting chemical being driven down to the ground by thedowndraft of blades before it can reach the crashed craft.

1. A method of combattingaircraft fires consisting of the 5 steps of:

a. positioning an emergency aircraft above a distressed aircraft inflight but a crash landing of which is imminent, b. maintaining saidemergency aircraft in said position during and after the crash landingof said distressed aircraft,

1 0 and c. ejecting clouds of flame-smothering heavier-than-air 2?aircraft, whereby said emergency aircraft is cooled and saidame-smothermg vapor is urged downwardly toward said dlS- tressedaircraft.

4. Apparatus for combatting aircraft fires comprising:

a. an emergency aircraft capable of assuming a flight position above anaircraft in flight but in distress and about to execute a crash'landing,and capable of maintaining said position before, during, and after saidcrash landing, and

b. means carried by said emergency aircraft for ejecting clouds offlame-smothering, heavier-than-air vapor, said ejecting means comprisinga tank carried by said emergency aircraft for containing a pressurizedliquid chemical solution which when ejected into the atmosphere burstsinto clouds of flame-smothering, heavier-than-air vapor, a plurality ofnozzles interconnected with said tank and through which said solution isejected, said nozzles being normally closed and divided into setsdirected downwardly and horizontally in various directions, and meanswhereby the nozzles of any of said sets of nozzles may be openedselectively.

5. Apparatus as recited in claim 4 wherein said emergency aircraft is ahelicopter equipped with the usual overhead propelling blades operableto create a strong downdraft of air around the fuselage thereof, saidnozzles being disposed beneath said blades, said downwardly directednozzles being of a spray type whereby the chemical solution ejectedtherefrom bursts into vapor close to the tips of the nozzles, and saidhorizontally directed nozzles being of a jet type whereby the chemicalsolution ejected therefrom remains in liquid jet form to a point notbeneath said propelling blades.

What I claim as new and desire'to protect by Letters Patent

1. A method of combatting aircraft fires consisting of the steps of: a.positioning an emergency aircraft above a distressed aircraft in flightbut a crash landing of which is imminent, b. maintaining said emergencyaircraft in said position during and after the crash landing of saiddistressed aircraft, and c. ejecting clouds of flame-smotheringheavier-than-air vapor from said emergency aircraft, whereby saiddistressed aircraft is enveloped in said vapor during and after itscrash landing.
 2. The method as recited in claim 1 wherein saidemergency aircraft is positioned either above or horizontally spacedapart from said distressed aircraft, and wherein said vapor clouds areejected from said emergency aircraft selectively either downwardly orhorizontally in any direction.
 3. The method as recited in claim 1 withthe additional step of directing a flow of cool air downwardly over saidemergency aircraft, whereby said emergency aircraft is cooled and saidflame-smothering vapor is urged downwardly toward said distressedaircraft.
 4. Apparatus for combatting aircraft fires comprising: a. anemergency aircraft capable of assuming a flight position above anaircraft in flight but in distress and about to execute a crash landing,and capable of maintaining said position before, during, and after saidcrash landing, and b. means carried by said emergency aircraft forejecting clouds of flame-smothering, heavier-than-air vapor, saidejecting means comprising a tank carried by said emergency aircraft forcontaining a pressurized liquid chemical solution which when ejectedinto the atmosphere bursts into clouds of flame-smothering,heavier-than-air vapor, a plurality of nozzles interconnected with saidtank and through which said solution is ejected, said nozzles beingnormally closed and divided into sets directed downwardly andhorizontally in various directions, and means whereby the nozzles of anyof said sets of nozzles may be opened selectively.
 5. Apparatus asrecited in claim 4 wherein said emergency aircraft is a helicopterequipped with the usual overhead propelling blades operable to create astrong downdraft of air around the fuselage thereof, said nozzles beingdisposed beneath said blades, said downwardly directed nozzles being ofa spray type whereby the chemical solution ejected therefrom bursts intovapor close to the tips of the nozzles, and said horizontally directednozzles being of a jet type whereby the chemical solution ejectedtherefrom remains in liquid jet form to a point not beneath saidpropelling blades.